1. Field of the Invention
The present invention relates to a method for producing powdery seasoning. More specifically, the present invention relates to a method for producing powdery seasoning, for example, powdery soy sauce.
2. Related Background Art
From the demand of diversified dietary life, a wide variety of instant foods have been developed in combination with seasonings for use in the foods. Seasonings for use in instant foods are mostly produced and processed in powdery forms. Furthermore, powdery seasonings may be stored under inappropriate conditions such as high temperature, high humidity and excess exposure for a considerably long period from the production into the hands of consumers.
Powdery seasoning is currently on production and supply, taking account of these potentially adverse conditions. However, it is impossible to anticipate all of the conditions to which such seasonings may possibly be exposed. Furthermore, the preventive measure against any adverse condition with an extremely low probability of occurrence will eventually cause prominent escalation of the production cost, which is not practical.
Powdery seasoning is entirely or partially in powder or granule form. A substance in powder or in granule form has a larger surface area per unit weight. Because powdery seasoning also contains a hygroscopic component such as sodium chloride, individual powdery particles or granules are bound together to form a mass, which readily coagulates, disadvantageously.
The coagulation of powdery seasoning gives the impression of deteriorated quality, which seriously damages the merchandise value. Prior to or after the occurrence of coagulation, the taste or flavor of powdery seasoning may eventually be deteriorated.
As conventional methods for preventing coagulation of powdery seasoning, it is known a method comprising adding and mixing an edible substance which turns to hydrophobic in a dry state, namely oxidized starch, processed starch such as phosphorylated starch, dextrin, naturally occurring gum such as gum arabic, or protein such as gelatin. Some of such methods have been used in a practical sense, for example, a method comprising adding dextrin so as to prevent coagulation of "powdery soy sauce", as disclosed in Japanese Patent unexamined Publication No. JP-A-64-039977.
However, the following problems are noted, concerning the preventive measures against coagulation of powdery seasoning according to these known methods.
That is, in case an edible substance which turns to hydrophobic in a dry state is mixed with the powdery seasoning and the like, it is necessary for the substance to add at a relatively high concentration, for example, about 10 to 30% by the weight ratio as the anhydride thereof.
These substances should never deteriorate the essential taste and flavor of the seasoning. Therefore, these substances should be selected from those substances with no taste or with taste as dry as possible.
When a substance with no taste or with taste as dry as possible is added to powdery seasoning to a final concentration at which the substance can exert an effect of preventing coagulation, powdery seasoning is consequently diluted, and thus the taste and flavor of the powdery seasoning is decreased per unit dose. In other words, potentially, the effect of powdery seasoning may be lowered apparently.
Furthermore, apparent change of powdery seasoning may be observed with addition of these substances, giving unnatural impression.
When a substance with an effect of preventing coagulation is added, an additional treatment such as further addition of sodium chloride or salt may be needed so as to recover and correct the deterioration of the taste and flavor per unit dose.
Compared with powdery seasoning of itself, most of edible substances turning hydrophobic in a dry state are substantially costly. Therefore, producing powdery seasoning having an effect of preventing coagulation with the addition of these substances may inevitably involve the increase of the production cost. Also, the increase of the production cost limits the range of selectable substances to be added.
During the production process of powdery seasoning, during the drying process in particular, spray drying is carried out in most cases. However, even a hydrophobic substance in a dry state forms a viscous solution when mixed with a raw material liquid seasoning, which is disadvantageous for handling. Still further, characteristically, a hydrophobic substance in a dry state is so hardly miscible with a raw material liquid seasoning at an initial stage that laborious extra works such as specific agitation procedure or heating may be required for homogeneous mixing of the substance with the liquid seasoning so as to prevent any development of coagulation or mass. Hence, the entire process will be complex. Further, adhesion onto the inner wall of a spray dryer may occur, resulting in a lower yield of products, or smooth operation of the dryer will be blocked. Otherwise, because the raw materials may be partially overheated during drying, various disadvantages such as the decomposition or denaturation of tasty components or flavor components may develop.
It is also noted that some edible substances turning hydrophobic in a dry state may generate by-products having "browning" actions of the resulting products during the drying process or under storage.
As has been described above, problems not yet overcome have been remarked for the known methods for preventing coagulation of powdery seasoning comprising adding an edible substance turning hydrophobic in a dry state. Conventionally, vast amounts of energetic technical efforts have been devoted toward the problems to be overcome. However, no essential counter-measure has been found yet.